1. Field of the Invention
The present invention relates to a small-sized vehicle, and more particularly, to a small-sized vehicle provided with a differential unit having a low profile for differential movements of rear-wheel axle shafts.
2. Description of Related Art
Conventionally, there is known a small-sized vehicle provided with a differential unit for differential movements of axle shafts. Such small-sized vehicle is disclosed in, for example, JP-A-2002-059754.
JP-A-2002-059754 described above discloses multi-wheeled drive vehicle provided with a differential part which is rotated by a transmission gear mechanism connected to an engine to achieve differential movements of rear wheels. The differential part of the multi-wheeled drive vehicle disclosed in JP-A-2002-059754 is provided with an input gear, which meshes with an output gear of the transmission gear mechanism, and driven (rotated) directly by the transmission gear mechanism.
In the case where a differential part is driven directly by a transmission gear mechanism as in the multi-wheeled drive vehicle disclosed in JP-A-2002-059754, however, it is necessary to increase a reduction ratio of an output gear and an input gear. Therefore, since a diameter of the input gear becomes large as compared with a diameter of the output gear, there is caused a problem that a differential part becomes large in a vertical direction.